When Bockatech’s EcoCore foam technology made its global debut at K three years ago, the company’s molded 430ml cup weighed 20g with a 10-second cycle time and skin-to-foam-to-skin wall 2 mm insulated. Ahead of K 2022 at Arburg’s Technology Days event in June, the company molded a 14g, 430ml cup in a 6-second cycle with a 2mm foam wall on a polypropylene All Rounder 470 S (PP) provided by Borealis. Bockatech’s technology works by taking a foam-laden melt – originally powdered or liquid chemical foaming agents (CFAs) were added to pellets before molding, now Trexel’s MuCell process can be applied to introduce nitrogen into the melt in the barrel – injecting this material quickly to allow a skin to form, then just as quickly opening the mold, which completes the foaming process outside the press. This can take a typical foam injection molding process with a cycle time of 60 seconds to 6 seconds, according to Bockatech.
Bockatech EcoCore Products
This K, the company will showcase products made with the technology at the Borealis booth, with which it partners as a material supplier for the process, as well as at the Trexel booth, with a mold running foam parts Bockatech. There, the company will again mold EcoCore cups using an Arburg 520 A All Rounder injection molding machine applying Trexel’s MuCell microcellular foam.
Bockatech notes that converters could still use CFAs to achieve foaming, but explains that EcoCore castings made with MuCell exhibit different cell structures than those made with the agents, resulting in containers that benefit from greater expansion and density reductions of up to 70%. The technology works on any existing “packaging specification” machine, says Bockatech, but switching to MuCell would mean converting the press cylinder to support this technology and adding the SCF (super critical liquid) delivery system. from Trexels.
Bockatech’s EcoCore innovation covers three main areas: mold design; plasticizing and processing parameters; and the use of a custom polypropylene blend including foaming agents. EcoCore is widely patented and Bockatech’s current business model is to license it to manufacturers and brands and provide technical know-how in addition to helping licensees design and build tools.
The company says that compared to a core foaming process, where the mold is opened slightly after injection, allowing the foam to expand, or processes where the foam is injected into the tool from the barrel , EcoCore consists of injecting plastic containing gas extremely quickly; create a layer of skin over the core and the cavity; then fully open the mold for a controlled foaming process on the outside of the tool. Bockatech calls this ROME (rapid open mold expansion), resulting in cycle times of 5-7 seconds and a weight saving of 50%.
The company claims the resulting containers are about 5 times stiffer than standard packaging of the same material and weight, with double the insulating properties. Containers can be decorated via IML, offset printing, screen printing and more. “Anything you can do to a polyolefin container, you can do to EcoCore,” says Bocking. At Technology Days, Bockatech CEO Henri Gaskjenn took a newly molded cup and placed it upside down on the floor and stood on it, his whole body weight having no effect on the container. .
Initially, the technology was developed to target reusable coffee cups, referred to as “fruit within reach,” according to Martin Blacher, director of Bockatech; and Chris Bocking, company founder. In addition to reusability, the company was looking for a recyclable mono-material cup with reduced density and insulating properties. Over the past three years, Blacher and Bocking say the company has targeted additional vertical markets in packaging and elsewhere. In addition to the insulating properties for hot beverages, the foam core also prevents condensation buildup for cold beverages in humid environments.
“The segment we are targeting is more sustainable packaging solutions,” says Blacher. “Where many sustainable packaging solutions fail today is that they are not cost competitive. We want to bring sustainable packaging to the market at competitive prices. For example, Blacher and Bocking note that moving away from single-use packaging, particularly if they don’t have a ready and robust recycling stream, can boost sustainability, but many reusable packaging today is quite heavy, which makes the number of times the package would need to be reused to reach a very high economic and carbon “break-even point”.
Part of Bockatech’s go-to-market strategy is to lock in a global brand and show that its technology is feasible at mass production scale. The company believes that if big brand owners were to partner with converters for marketing, it could accelerate adoption.
“Converters have capital expenditure related to existing molds,” says Bocking. “It would be difficult for them to pre-invest before a brand was on board.”
Beyond the reusable cup, Bockatech says it has seen significant weight savings in caps and closures, using its technology to reduce weight while increasing maximum loads. Other potential applications would be hot water canners, reusable bowls as well as clam shells for food service and buckets. The company primarily works in cylindrical shapes at present, but Blacher says that as the platform progresses, it will take on other shapes over the next few years.
Read: Responding to the challenge of sustainable development through digitization
In addition to the foam core, parts can be designed that combine opaque foam sections as well as transparent sections. By controlling where foaming occurs, Bockatech says it can design in areas where two skins touch in the mould. These then solidify and result in transparent sections around the foam areas for a distinct contrast.
Bockatech says mold design and manufacture for EcoCore is important, especially when it comes to achieving a consistent wall thickness and temperature profile across the entire surface. “We’re pickier,” Bocking said. “If you had a thicker hot spot on the tool surface, you would get different sizes of expansion.” In terms of cavitation, the company envisions more cavities for smaller parts, possibly 24 or 32, and for larger parts, such as cups, 4 or 8 cavities, although Bockatech explains that faster cycles can also mean greater production from a low cavitation tool. .
Landscape photo credit: Bockatech